Work conveying system and traveling path sealing structure in the work conveying system

ABSTRACT

In a work conveying system including at least a work holder for holding a work and a horizontal mover for moving the work holder horizontally in an upper ceiling space within a clean room, the work being conveyed to each of plural processing apparatuses. The horizontal mover has at least one linear moving mechanism including a duct with an internal guide, a traveling body engaging the guide and traveling through the traveling path defined by the duct, and a slider connected to the traveling body for travel with the traveling body on the exterior of the traveling path. The work holder is attached to the slider. Air cleaners are disposed at suitable intervals in the traveling path to clean the air therein and to discharge the cleaned air to the exterior. The traveling path accommodates a drive source, a drive mechanism, and a power supply.

BACKGROUND OF THE INVENTION

[0001] 1. Field of the Invention

[0002] The present invention relates to a work conveying system and atraveling path sealing structure in the work conveying system.Particularly, the present invention is concerned with an improvement ofa work conveying system and a traveling path sealing structure wherein,in a production line installed within a clean room for the productionof, for example, semiconductor components, liquid crystal displaypanels, medical supplies, drugs, or processed foods, dust generated inthe interior of a traveling path (guide rail) in the work conveyingsystem is prevented from leaking out into the clean room, the workconveying system being adapted to convey a work to each of pluralprocessing apparatuses while allowing the work to circulate among theprocessing apparatuses.

[0003] 2. Description of the Prior Art

[0004] In a semiconductor integrated circuit or a liquid crystal displaypanel, the deposition of dust causes a lowering of product yield. As tomedical supplies, drugs and processed foods, it is desirable for them tobe produced in a sterile and sanitary environment. In this connection,intra-clean room production lines are in operation in a wide variety offields including those production fields, and various technicaldevelopments have been made with respect to various processing chambersand work conveying systems installed within clean rooms.

[0005] As to the work conveying system, an overhead traveling type workconveying system has been developed. According to this work conveyingsystem, a layout mode of various processing apparatuses to be installedwithin a clean room is difficult to be restricted and it is possible toselect an optimum layout, that is, it is possible to utilize theinterior of the clean room effectively and thereby possible to reducethe equipment cost and operation cost of the clean room. The adoption ofsuch an optimal layout is advantageous also in that the work conveyingsystem which can be a generation source of dust (particles) can be keptaway from apparatuses such as various processing chambers installedwithin the clean room.

[0006] The applicant in the present case has previously invented a workconveying system provided with moving means capable of moving a workholding means in arbitrary three-dimensional directions in the upperceiling space within the clean room and applied for a patent (seeJapanese Patent Laid Open No. 2000-243808).

[0007] In this work conveying system, a pair of horizontal fixed guiderails are laid in parallel within a ceiling space and one or pluralhorizontal traveling guide rails are laid between the pair of fixedguide rails so that they can travel along the fixed guide rails. On eachtraveling guide rail is provided a traveling block which can travelalong the traveling guide rail. A horizontal moving means is constitutedby the fixed guide rails, traveling guide rail(s), and a travelingblock. Further, the traveling block is provided with a vertical movingmeans which can move the work holding means up and down. Athree-dimensional moving means is constituted by the horizontal movingmeans and the vertical moving means.

[0008] The fixed and traveling guide rails, which are each in anelongated duct shape, contain a drive portion (including a drive motorand a drive mechanism) for the traveling guide rail and the travelingblock, also contain a power supply means, and are communicated with eachother. Dust (particles) generated from the drive portion and variousslide portions is confined into ducts which constitute the fixed andtraveling guide rails and is sucked in from one end of a communicationpath and is discharged to the exterior of the clean room. In this waycontamination in the clean room caused by dust present within the ductswhich constitute the guide rails is prevented to a considerable extent.

[0009] However, the communication path which provides communicationbetween the fixed guide rails and the traveling guide rail(s) is longand, while the dust present within the ducts as communicationconstituents of the guide rails is sucked in from one end of thecommunication path and is discharged to the exterior of the clean room,there is a fear that the dust may leak to a lower portion of the cleanroom from a gap in the communication path, especially from an elongatedgap in which a connecting member for connection between the travelingguide rail(s) and the drive portion thereof extends through the duct asa constituent of a fixed guide rail or from an elongated gap in which aconnecting member for connection between the traveling block and thedrive portion thereof extends through the duct as a constituent of thetraveling guide rail, with a consequent likelihood of lowering in thedegree of cleanness of the clean room.

[0010] In FIG. 17 there is illustrated a sealing structure in this workconveying system, in which an elongated gap 028 formed in a portionwhere a connecting member 022 for connection between a traveling guiderail 015 and a drive portion thereof (including a drive motor 023 and adrive roller 026) extends through a duct 017 as a constituent of a fixedguide rail 014 is sealed. In this sealing structure, the connectingmember 022 has a zigzag-bent sectional shape and shield plates 041 a and041 b are inserted deep into slit portions (slits 022 a and 022 b) ofthe connecting member 022, thereby constituting a labyrinth to preventdust generated in the drive and slide portions in the duct from leakingout into the clean room. However, even with such a labyrinth structure,since the suction of dust is performed through a long communicationpath, it has so far been impossible to completely prevent the dustpresent in the duct from leaking out to the lower portion of the cleanroom.

[0011] Other examples of overhead traveling type work conveying systemsare disclosed in Japanese Patent Laid Open Nos. 1993-116885, 1993-39030,and 1995-291123. In these work conveying systems, a traveling rollerprovided in a traveling body is adapted to roll on a rail laid on aceiling, whereby the traveling body travels. But a drive portion todrive the traveling roller is covered with a cover member attached tothe traveling body itself, so that dust generated in the drive portionand a slide portion between the traveling roller and the rail is easy tobe released into the clean room. Since the above conventional techniquesare not dedicated to a clean room, they are not applicable to asatisfactory extent to a clean room for which a high degree of cleannessis required.

SUMMARY OF THE INVENTION

[0012] It is an object of the present invention to solve theabove-mentioned problems involved in the conventional overhead travelingtype work conveying system and provide a work conveying system and atraveling path sealing structure in the work conveying system which canprevent dust generated from a drive portion(s) and various slideportions in a traveling path of the work conveying system from leakingout into a clean room, the work conveying system comprising fixed guiderails and a traveling guide rail(s), and thereby prevent a lowering inthe degree of cleanness of the clean room more effectively.

[0013] For achieving the above-mentioned object, in a first aspect ofthe present invention there is provided a work conveying systemcomprising a least a work holding means for holding a work and ahorizontal moving means for moving the work holding means horizontallyin an upper ceiling space within a clean room, the work being conveyedto each of plural processing apparatuses while circulating among theprocessing apparatuses, wherein the horizontal moving means has at leastone linear moving mechanism, the linear moving mechanism comprising atraveling path covered with a duct and having a guide portion in theinterior thereof, a traveling body adapted to engage the guide portionand travel through an interior space of the traveling path, and a sliderconnected to the traveling body and adapted to travel together with thetraveling body in the exterior of the traveling path, the work holdingmeans or another linear moving mechanism being attached to the slider,and cleaning means are disposed at suitable intervals in the travelingpath to clean the air present within the traveling path and dischargethe cleaned air to the exterior.

[0014] Since the invention in the first aspect is constructed as above,there can be obtained the following effects.

[0015] Since the traveling body, which is one constituent of the linearmoving mechanism provided in the horizontal moving means, is adapted toengage the guide portion located within the traveling path covered witha duct and travel through the interior space of the traveling path, dustgenerated from a slide portion in which the traveling body and the guideportion are engaged with each other is confined into the duct and thepossibility of its leaking out into the exterior clean room isdecreased. Besides, since cleaning means for cleaning air present withinthe traveling path and discharging it to the exterior are disposed atsuitable intervals in the traveling path, dust present in the travelingpath is sucked and cleaned in the unit of a relatively short travelingpath and the cleaned air is discharged to the exterior. Thus, it ispossible to greatly decrease the proportion of dust leaking out into theclean room. Consequently, it becomes possible to keep high the degree ofcleanness in the clean room.

[0016] In a second aspect of the present invention there is provided, incombination with the above first aspect, a work conveying system whereina drive source, a drive mechanism, and a power supply means, which arefor the traveling body, are accommodated in the interior of thetraveling path, at least the drive source being integral with thetraveling body.

[0017] According to this construction, the drive portion (including thedrive source and the drive mechanism) is also positioned in the interiorof the traveling path, whereby the possibility that the dust generatedfrom the drive portion may leak out into the clean room located outsidethe duct is decreased. As a result, it becomes possible to keep higherthe degree of cleanness in the clean room.

[0018] In a third aspect of the present invention there is provided, incombination with the above first or second aspect, a work conveyingsystem wherein a base member serving as a base of a guide member havingthe guide portion constitutes a part of the duct, the guide member andthe base member being formed by integral molding of the same material.

[0019] According to this construction, the guide member and the basemember which constitutes a part of the duct can be fabricated at a lowcost by drawing aluminum for example.

[0020] Further, in a fourth aspect of the present invention there isprovided, in combination with any of the above first to third aspects, awork conveying system wherein in the horizontal moving means a pluralityof the linear moving mechanisms are used in combination to permit thehorizontal moving means to move arbitrarily in a horizontal plane in theupper ceiling space within the clean room.

[0021] According to this construction, the work conveying system can beconstructed such that in the upper ceiling space within the clean room,fixed guide rails each provided with an individual linear movingmechanism are disposed horizontally in parallel on both sides, atraveling guide rail provided with an individual linear moving mechanismis laid between the fixed guide rails so that it can travel along bothfixed guide rails, and a traveling block adapted to travel while holdingthe work is attached to the linear moving mechanism provided in thetraveling guide rail so that the traveling block can travel along thetraveling guide rail. Thus, a horizontal moving means capable of movingarbitrarily in a horizontal plane in the ceiling space can beconstructed in a simple manner.

[0022] In a fifth aspect of the present invention there is provided, incombination with any of the above first to fourth aspects, a workconveying system wherein the work holding means is attached to theslider through a vertical moving means for moving the work holding meansvertically.

[0023] According to this construction, a work conveying system providedwith a three-dimensional moving means which permits arbitrary movementof the work holding means in a space within the clean room can beconstructed in an extremely simple manner.

[0024] In a sixth aspect of the present invention there is provided awork conveying system comprising at least a work holding means forholding a work and a horizontal moving means for moving the work holdingmeans horizontally in an upper ceiling space within a clean room, thework being conveyed to each of plural processing apparatuses whilecirculating among the processing apparatuses, wherein the horizontalmoving means has at least one linear moving mechanism, the linear movingmechanism comprising a traveling path covered with a duct and having aguide portion in the interior thereof, a traveling body adapted toengage the guide portion and travel through an interior space of thetraveling path, and a slider connected to the traveling body and adaptedto travel together with the traveling body in the exterior of thetraveling path, the work holding means or another linear movingmechanism being attached to the slider, and a deformable sealing meansis provided in an elongated gap portion in which a connecting member forconnecting the slider to the traveling body extends through the duct andtravels along the traveling path, the sealing means covering theelongated gap portion without obstructing the travel of the connectingmember.

[0025] In the sixth aspect constructed as above there can be obtainedthe following effects.

[0026] Since the traveling body as one constituent of the linear movingmechanism provided in the horizontal moving means of the work conveyingsystem is adapted to engage the guide portion located within thetraveling path covered with the duct and travel through the interiorspace of the traveling path, dust generated from a slide portion inwhich the traveling body and the guide portion are engaged with eachother is confined into the duct and the possibility of its leaking outinto the exterior clean room is decreased. Besides, since a deformablesealing means is provided in an elongated gap portion in which theconnecting member for connecting the slider to the traveling bodyextends through the duct which covers the traveling path, the sealingmeans covering the elongated gap portion without obstructing the travelof the connecting member, the proportion of dust leaking out from theelongated gap portion into the clean room can be greatly decreased.Consequently, it becomes possible to keep high the degree of cleannessin the clean room.

[0027] Further, in a seventh aspect of the present invention there isprovided a traveling path sealing structure in a work conveying system,the work conveying system including at least one linear movingmechanism, the linear moving mechanism comprising a traveling pathcovered with a duct and having a guide portion in the interior thereof,a traveling body adapted to engage the guide portion and travel throughan interior space of the traveling path, and a slider connected to thetraveling body and adapted to travel together with the traveling body inthe exterior of the traveling path, the working holding means or anotherlinear moving mechanism being attached to the slider, wherein adeformable sealing means is provided in an elongated gap portion inwhich a connecting member for connecting the slider to the travelingbody extends through the duct and travels along the traveling path, thesealing means covering the elongated gap portion without obstructing thetravel of the connecting member.

[0028] According to this construction there can be obtained thefollowing effects.

[0029] Since the traveling body as one constituent of the linear movingmechanism provided in the work conveying system is adapted to engage theguide portion located in the interior of the traveling path covered withthe duct and travel through the interior space of the traveling path,dust generated from a slide portion where the traveling body and theguide portion engage each other is confined into the duct and thepossibility of its leaking out into the exterior clean room isdecreased. Besides, since a deformable sealing member is provided in anelongated gap portion in which the connecting member for connecting theslider to the traveling body extends through the duct which covers thetraveling path, the sealing means covering the elongated gap portionwithout obstructing the travel of the connecting member, it is possibleto greatly decrease the proportion of dust leaking out to the exteriorfrom the elongated gap portion. Consequently, the degree of cleanness ofthe external environment can be kept high.

[0030] In an eighth aspect of the present invention there is provided,in combination with the above seventh aspect, a traveling path sealingstructure in a work conveying system wherein the sealing means is anexpansion member in the shape of bellows which normally extendsnaturally to seal the elongated gap portion.

[0031] According to this construction, by merely providing in theelongated gap portion a bellows-like expansion member which is commonlyused as a sealing member or a protective cover member, there can beeasily obtained a deformable sealing means which covers the elongatedgap portion without obstructing the travel of the connecting member.

[0032] In a ninth aspect of the present invention there is provided, incombination with the above seventh aspect, a traveling path sealingstructure in a work conveying system wherein the sealing member is anexpansion member which normally extends by virtue of magnetism to sealthe elongated gap portion.

[0033] According to this construction, by magnetizing a lower edge of acommonly-used expansion member which lower edge extends along theelongated gap and by attracting the lower edge magnetically, theexpansion member is extended to cover the elongated gap portion.Consequently, in a portion where the connecting member does not pass,the sealing of the elongated gap portion is ensured, with no obstructionto a smooth travel of the connecting member.

[0034] Further, in a tenth aspect of the present invention there isprovided, in combination with the above eighth or ninth aspect, atraveling path sealing structure in a work conveying system wherein whenlooking in the traveling direction of the connecting member, in front ofthe connecting member are provided a first seal holding member forholding the sealing means in an initially closed state and a first sealopening member for subsequently opening the sealing member while theconnecting member travels through the elongated gap portion, and at therear of the connecting member are provided a second seal opening memberfor holding the sealing means in an initially opened state and a secondseal holding member for subsequently closing the sealing member whilethe connecting member travels through the elongated gap portion.

[0035] According to this construction, closure of the elongated gapportion by the sealing means in a portion where the connecting memberdoes not pass and release (opening) of the closure of the elongated gapportion by the sealing means in a portion where the connecting memberpasses are performed forcibly, so that both positive sealing of theelongated gap portion and smooth travel of the connecting member can beeffected simultaneously.

[0036] In an eleventh aspect of the present invention there is provided,in combination with the above seventh aspect, a traveling path sealingstructure in a work conveying system wherein the sealing means isconstituted by a chain and normally hangs down naturally to seal theelongated gap portion.

[0037] According to this construction, by merely providing a chain as acommonly-used part in the elongated gap portion, it is possible toeasily obtain a deformable sealing means which covers the elongated gapportion without obstructing the travel of the connecting member.

[0038] In a twelfth aspect of the present invention there is provided,in combination with the above seventh aspect, a traveling path sealingstructure in a work conveying system wherein the sealing means comprisesa pair of upper and lower elastic tubular members which press theconnecting member constantly from above and below, and when theconnecting member travels through the elongated gap portion, theconnecting member travels while pushing aside the pair of upper andlower elastic tubular members vertically, while after passage of theconnecting member, the pair of upper and lower elastic tubular memberscan immediately revert to their original shape.

[0039] According to this construction, by only providing the elongatedgap portion with a pair of upper and lower elastic tubular members ascommonly-used components, e.g., elastic tubular members (tubes or thelike) having a bellows shape or a balloon shape in section, there can beeasily obtained a deformable sealing means which covers the elongatedgap portion without obstructing the travel of the connecting member.

BRIEF DESCRIPTION OF THE DRAWINGS

[0040]FIG. 1 is a perspective view of a production line in a clean roomto which is applied a work conveying system according to an embodiment(first embodiment) of the invention described in the foregoing first tofifth aspects;

[0041]FIG. 2 is a cross sectional view of a linear moving mechanismprovided in a horizontal moving means used in the work conveying system,with a cross sectional view of a cleaning means overlapped thereon;

[0042]FIG. 3 is a sectional view as seen in the direction of arrowsIII-III in FIG. 2;

[0043]FIG. 4 is a partial sectional side view of a linear movingmechanism provided in a work conveying system according to an embodiment(second embodiment) of the invention described in the foregoing sixth toeighth aspects and tenth aspect, or provided in a horizontal movingmeans used in the work conveying system, as cut at a positioncorresponding to line IV-IV in FIG. 2 and as seen in the arroweddirection;

[0044]FIG. 5 is a sectional side view of only a connecting memberportion as taken out and seen from FIG. 4, and is a sectional view asseen in the arrowed direction V-V in FIG. 6;

[0045]FIG. 6 is a plan view of FIG. 5, partially broken away;

[0046]FIG. 7 is a sectional view as seen in the arrowed directionVII-VII in FIG. 4;

[0047]FIG. 8 is a sectional view as seen in the arrowed directionVIII-VIII in FIG. 4;

[0048]FIG. 9 is a view similar to FIG. 7, showing a modified example ofa sealing means used in the work conveying system of the secondembodiment;

[0049]FIG. 10 is a partial sectional side view of a linear movingmechanism provided in a work conveying system according to an embodiment(fourth embodiment) of the invention described in the foregoing eleventhaspect, as cut at a position corresponding to line IV-IV in FIG. 2 andas seen in the arrowed direction;

[0050]FIG. 11 is a sectional view as seen in the arrowed direction XI-XIin FIG. 10;

[0051]FIG. 12 is a sectional view as seen in the arrowed directionXII-XII in FIG. 10;

[0052]FIG. 13 is a partial sectional side view of a linear movingmechanism provided in a work conveying system according to an embodiment(fifth embodiment) of the invention described in the foregoing twelfthaspect, as cut at a position corresponding to line IV-IV in FIG. 2 andas seen in the arrowed direction;

[0053]FIG. 14 is an enlarged sectional view as seen in the arroweddirection XIV-XIV in FIG. 13;

[0054]FIG. 15 is a sectional view showing a modified example of asealing means used in the work conveying system of the fifth embodiment,in which a cut position is different from that in FIG. 14;

[0055]FIG. 16 is a sectional view showing the modified example, in whicha cut position is the same as in FIG. 14; and

[0056]FIG. 17 is a cross sectional view of a linear moving mechanismprovided in a horizontal moving means used in a conventional workconveying system.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

[0057] An embodiment (first embodiment) of the invention described inthe foregoing first to fifth aspects will be described below withreference to FIGS. 1 to 3.

[0058]FIG. 1 is a perspective view of a production line in a clean roomto which a work conveying system of the first embodiment is applied,FIG. 2 is a cross sectional view of a linear moving mechanism providedin a horizontal moving means used in the work conveying system, with across sectional view of a cleaning means overlapped thereon, and FIG. 3is a sectional view as seen in the arrowed direction III-III in FIG. 2.

[0059] In a production line 1 installed within a clean room to which thework conveying system of the first embodiment is applied, as shown inFIG. 1, plural processing chambers (processing apparatuses) 3 arearranged side by side in two rows on a floor surface 2 in the cleanroom, and an interface device 4 being attached to a front end of eachprocessing chamber 3.

[0060] The processing chambers 3 are apparatuses for conductingdifferent processings for works one after another. Taking tact timebalance in work processing into account, a plurality of same processingchambers may be included in the production line. For example, theprocessing chambers 3 are semiconductor wafer processing apparatuses forsubjecting a semiconductor wafer to such processings as the applicationof resist, exposure, development, ion implantation, annealing, andsputtering. With such processings for a semiconductor wafer in mind, thefollowing description is now provided. The interface device 4 associatedwith each semiconductor wafer processing apparatus is constituted by adevice called FOUP opener.

[0061] The interface devices 4 constitute buffer spaces for isolatingthe processing chambers 3 and the clean room from each other. Thedelivery of works in each processing chamber 3 is performed through theassociated interface device 4. A work inlet/outlet 5 in each interfacedevice 4 is hermetically sealed except when loading and unloading awork.

[0062] Adjacent processing chambers 3 and interface devices 4 arearranged through a minimum maintenance area required for works whichmaintenance personnel or operator personnel performs. Thus, the floorarea of the clean room is minimized to make the most of the clean roomand attain an efficient conveyance of works by the work conveying system10 to be described later. But it is not always necessary that theprocessing chambers 3 be arranged in plural rows, nor is specified inwhich direction a front side (the side where each interface device 4 isprovided) should face. A certain degree of random arrangement isallowed.

[0063] In an upper space within the clean room is installed the workconveying system 10 for conveying a hermetically sealed container (FOUP)6 to the processing chambers 3. Works are conveyed in a hermeticallysealed state within the hermetically sealed container 6 in order to keepa high degree of cleanness required. On the floor surface 2 is provideda space for the travel of work carriers 7. When a work carrier 7receives the hermetically sealed container 6 which has been conveyedfrom outside the clean room, the work carrier 7 travels up to apredetermined position along a rail which is laid there, and deliversthe container 6 to the work conveying system 10.

[0064] The work conveying system 10 is provided with work holding means11 for holding the hermetically sealed container 6, horizontal movingmeans 12 for moving the work holding means 11 horizontally in an upperceiling space within the clean room, and vertical moving means 13constituted by an articulated arm and provided in the horizontal movingmeans 12. As noted earlier, the work conveying system 10 conveys works(the hermetically sealed container 6) to each processing chamber 3 whilecirculating among plural processing chambers in a predeterminedprocessing sequence. In the vertical moving means 13, the articulatedarm is extended and contracted to raise and lower the work holding means11, thereby making it possible to delivery works between the workholding means 11 and each of the processing chambers 3. Athree-dimensional moving mechanism is constituted by both horizontalmoving means 12 and vertical moving means 13.

[0065] As shown in FIG. 1, the horizontal moving means 12 comprises apair of horizontal fixed guide rails 14 which are laid in parallel inthe upper ceiling space within the clean room, a traveling guide rail 15laid between the pair of fixed guide rails 14, and a traveling block 16disposed on the traveling guide rail 15 and adapted to travel along thetraveling guide rail 15. The traveling guide rail 15 travels along thepair of fixed guide rails 14 and traveling block 16 travels along thetraveling guide rail 15, whereby in the upper ceiling space within theclean room the horizontal moving means 12 can move arbitrarily in ahorizontal plane sandwiched in between the pair of fixed guide rails 14.Consequently, the vertical moving means 13 and the work holding means 11can be moved linearly from a certain position to another positionlocated on the opposite side with a central passage therebetweensandwiched. Actually, the vertical moving means 13 is provided in thehorizontal moving means 12 by being attached to the traveling block 16.A suitable spacing between the pair of horizontal fixed guide rails 14is set according to how the processing chambers 3 are arranged(installed position and direction). The said spacing may be taken overthe full width of the clean room.

[0066] Next, a detailed description will be given below about thestructure of a linear moving mechanism provided in the horizontal movingmeans 12 for moving the traveling guide rail 15 along each of the pairof fixed guide rails 14 or a linear moving mechanism for moving thetraveling block 16 along the traveling guide rail 15. Since both linearmoving mechanisms are of a structure common to each other, a detaileddescription will be given below about the structure of only the linearmoving mechanism for moving the traveling guide rail 15 along each ofthe pair of fixed guide rails 14.

[0067] In the linear moving mechanism for moving the traveling guiderail 15 along each of the pair of fixed guide rails 14, as shown inFIGS. 2 and 3, a traveling body 20 engages a guide portion 18 a providednearly centrally in the interior (traveling path A) of a duct 17 whichconstitutes an outer shell of each of the fixed guide rails 14, andtravels along the guide portion 18 a. Further, a slider 21 is connectedto the traveling body 20 through a connecting member 22 and thetraveling guide rail 15 is mounted to the slider 21. As the travelingbody 20 travels along the guide portion 18 a, the traveling guide rail15 travels along the pair of fixed guide rails 14 outside the travelingpath A together with the traveling body 20 through the connecting member22 and the slider 21. In the linear moving mechanism for causing thetraveling block 16 to travel along the traveling guide rail 15, thetraveling block 16 is mounted to the slider 21. For diminishing stressimposed on the connecting member 22, the guide portion 18 a may bepositioned close to an elongated gap 28 to be described later.

[0068] The duct 17 is constituted by an integral connection of an upperduct half 17 a and a base member 19 of a lower duct half 17 b. In theinterior of the duct 17 is defined the traveling path A of the travelingbody 20 which determines a track of the traveling guide rail 15.

[0069] The lower duct half 17 b is relatively thick-walled and is formedin a chevron-like sectional shape as a whole in which a guide member 18having the guide portion 18 a is erected on the base member 19 at atransversely central position. The guide portion 18 a corresponds to asubstantially upper half portion of the guide member 18, whereby thetravel of the traveling body 20 is guided through linear bushings 26 andlinear guide rails 29 which will be described later. The base member 19constitutes a base of the guide member 18. Actually, the lower duct half17 b is integrally formed by drawing of aluminum for example.

[0070] The upper duct half 17 a is relatively thin-walled and covers thelower duct half 17 b from above. Both upper and lower duct halves coverthe traveling path A while forming a substantially hermetically sealedduct 17. The upper duct half 17 a is formed by a thin metallic orsynthetic resin plate and is attached to the lower duct half 17 bremovably to facilitate maintenance.

[0071] In the interior of the traveling path A are accommodated a motor23 as a drive source for driving the traveling body 20, a drivemechanism for the traveling body, and a movable cable 27 as a powersupply means, of which the motor 23 is integral with the traveling body20.

[0072] As shown in FIGS. 2 and 3, the traveling body 20 is constitutedby a relatively thick-walled, rigid member having a J-shaped section.Linear bushings 26 are fixed at a total of four upper, lower and right,left positions to an inner surface of a long leg-side wall of theJ-shaped section. The motor 23 is fixed to a lower end of a shortleg-side wall of the J-shaped section and a pinion 24 is connected to anoutput shaft of the motor 23. A rack 25 is in mesh with the pinion 24,the rack 25 being fixed to the wall of the guide portion 18 a on theside opposite to the side where a pair of linear guide rails 29 arefixed. The linear bushings 26 and the linear guide rails 29 are engagedwith each other. Therefore, when the motor 23 operates, the pinion 24and the rack 25 mesh with each other and the traveling body 20 moveslinearly along linear tracks of the linear guide rails 29 relative tothe guide portion 18 a. The pinion 24 and the rack 25 constitute a drivemechanism for the traveling body 20, and the motor 23, pinion 24 andrack 25 as a whole constitute a drive portion for the traveling body 20.

[0073] One side edge of the connecting member 22, which is constitutedby a relatively thick-walled, rigid plate member, is fixed to an outersurface (the side opposite to the side where the linear bushings 26 areinstalled) of the long leg-side wall of the J section of the travelingbody 20 in the longitudinal direction of the traveling body 20. Theopposite side edge of the connecting member 22 extends up to the outsideof the duct 17 through the elongated gap 28 formed on one side of theduct and the slider 21 is integrally connected and fixed to the oppositeside edge of the connecting member. As noted earlier, the travelingguide rail 15 or the traveling block 16 is mounted to the slider 21. Onone side of the duct 17, mating surfaces of the upper duct half 17 a andthe lower duct half 17 b are opposed to each other through a spacingwhich permits the connecting member 22 to pass therethrough, whereby theelongated gap 28 is defined.

[0074] One end of the movable cable 27 serving as a power supply meansis fixed to the bottom of the duct 17, while the opposite end thereof isfixed to an outer surface of an upper wall of the traveling body 20, andat an intermediate portion between the one and opposite ends the movablecable 27 is bent in U shape. As the traveling body 20 travels, themovable cable 27 advances and retreats its bent position to supply themotor 23 with electric power fed from the interior of the factoryconcerned. Though not shown in detail, this electric power is branchedhalfway from the movable cable 27 and is conducted to the exterior ofthe duct 17 along the connecting member 22 and fed to the drive motor inthe linear moving mechanism provided in the traveling guide rail 15mounted to the slider 21 and to the drive motor in the vertical movingmeans suspended from the traveling block 16. Electric power may becollected through a current collector means from a power transmissionline laid beforehand into the traveling path A instead of the movablecable 27.

[0075] As shown in FIG. 2, the drive portion of the traveling body 20and a slide portion in which the traveling body 20 rubs against theguide portion 18 a, etc. as it travels, are confined to a nearly centralarea of the duct 17 which is surrounded substantially by the travelingbody 20 and a casing of the motor 23. Thus, the drive portion and theslide portion are spaced a distance through a wall from the elongatedgap 28, so that dust generated in these portions is difficult to leakout into the clean room through the elongated gap 28.

[0076] On the opposite side of the duct 17 which defines the travelingpath A there are disposed cleaning means 30, as shown in FIG. 2. Thecleaning means 30, which are each made up of a fan 31 and a filter 32,are arranged at suitable intervals in the longitudinal direction of theduct 17 according to the length of the duct and according to thecapacity of the fan 31. The cleaning means 30 clean dust(particles)-containing air present within the traveling path A betweenadjacent cleaning means 30 and discharge the cleaned air into theexterior clean room, whereby the cleanness in the clean room ismaintained at a high degree.

[0077] The horizontal moving means 12, for which three sets of the abovelinear moving mechanisms are used in combination, is constituted as atwo-dimensional moving mechanism comprising the pair of horizontal fixedguide rails 14, the traveling guide rail 15 laid between the pair offixed guide rails 14, and the traveling block 16 disposed on thetraveling guide rail 15 and adapted to travel along the traveling guiderail 15. This two-dimensional moving mechanism is movable arbitrarily ina horizontal plane in the upper ceiling space within the clean room. Thenumber of the linear moving mechanisms to be combined is determined asnecessary. For example, if another traveling guide rail 15 is laidbetween the pair of fixed guide rails 14 and another traveling block 16is mounted on the traveling guide rail 15, another three sets of linearmoving mechanisms are used in combination.

[0078] Since this first embodiment is constructed as above, there can beattained the following effects.

[0079] Since the traveling body 20 as one constituent of each linearmoving mechanism provided in the horizontal moving means 12 is adaptedto engage the guide portion 18 a located within the traveling path Acovered with the duct 17 and travel through the interior space of thetraveling path A, dust generated from the slide portion in which thetraveling body 20 and the guide portion 18 a are engaged with each otheris confined into the duct 17 and the possibility of its leaking out intothe exterior clean room is diminished. Besides, since the motor 23serving as a drive source of the traveling body 20 is integral with thetraveling body 20, the drive portion (including the drive motor 23,pinion 24 and rack 25) of the traveling body 20 is also positioned inthe interior of the traveling path A and hence the possibility that dustgenerated from the drive portion may leak out into the clean room isalso diminished. In the traveling path A, moreover, since cleaning means30 for cleaning air present in the interior of the traveling path A anddischarging cleaned air to the exterior are disposed at suitableintervals, dust present in the traveling path A is sucked and cleaned inthe unit of a relatively short traveling path length and is dischargedinto the exterior clean room, whereby the proportion of dust leaking outinto the clean room can be greatly diminished. Consequently, it becomespossible to maintain the cleanness in the clean room at a high degree.

[0080] Additionally, since the slide portion between the traveling body20 and the guide portion 18 a and the drive portion of the travelingbody 20 are positioned nearly centrally, or in the vicinity thereof, inthe interior of the traveling path A covered with the duct 17, that is,since the drive portion and the slide portion are positioned relativelyfar from the elongated gap 28 portion in which the connecting member 22for connecting the slider 21 to the traveling body 20 passes through theduct 17 which covers the traveling path A, the possibility that the dustgenerated from those drive portion and slide portions may be dischargedinto the clean room through the elongated gap 28 portion is so muchdecreased. Consequently, the interior of the clean room can be kept at astill higher degree of cleanness.

[0081] The base member 19 serving as a base of the guide member 18having the guide portion 18 a constitutes a part (a lower half) of theduct 17 and an integral body (the lower duct half 17 b) of both guidemember 18 and base member 19 is formed integrally by drawing the samealuminum material and therefore can be fabricated at a low cost.

[0082] In the horizontal moving means 12, moreover, plural sets oflinear moving mechanisms are used in combination to permit arbitrarymovement of the horizontal moving means in a horizontal plane in theupper ceiling space within the clean room. Therefore, in the upperceiling space within the clean room, for example if fixed guide rails 14each provided with an individual linear moving mechanism are disposedhorizontally in parallel on both sides, if a traveling guide rail 15provided with an individual linear moving mechanism is laid between thefixed guide rails 14 so that it can travel along both fixed guide rails14, and if a traveling block 16 adapted to hold works and travel ismounted to the linear moving mechanism provided in the traveling guiderail 15 so that it can travel along the traveling guide rail 15, therecan be easily constituted the horizontal moving means 12 which can movearbitrarily in a horizontal plane in the ceiling space.

[0083] Further, since the work holding means 11 is mounted to thetraveling block 16 through the vertical moving means 13 which is formoving the work holding means 11 up and down and since the travelingblock 16 is mounted to the slider 21, the work conveying system 10provided with a three-dimensional moving means which permits arbitrarymovement of the work holding means 11 in a space within the clean roomcan be constituted in an extremely simple manner.

[0084] Next, the following description is now provided about anembodiment (second embodiment) of the invention described in theforegoing sixth to eighth and tenth aspects, which is illustrated inFIGS. 4 to 8.

[0085]FIG. 4 is a partial sectional side view of a linear movingmechanism provided in a work conveying system of this second embodimentor in a horizontal moving means used therein, as cut at a positioncorresponding to line IV-IV in FIG. 2 and as seen in the arroweddirection, FIG. 5 is a sectional side view of only a connecting memberportion as taken out and seen from FIG. 4, and is a sectional view asseen in the arrowed direction V-V in FIG. 6, FIG. 6 is a partiallybroken-away plane view of FIG. 5, FIG. 7 is a sectional view as seen inthe arrowed direction VII-VII in FIG. 4, and FIG. 8 is a sectional viewas seen in the arrowed direction VIII-VIII in FIG. 4. Portions common tothe work conveying system of the first embodiment are identified by thesame reference numerals as in the first embodiment.

[0086] In comparison with the linear moving mechanism provided in thehorizontal moving means 12 in the work conveying system 10 of the firstembodiment, a linear moving mechanism provided in a work conveyingsystem 10 of this second embodiment or in a horizontal moving means 12used therein is different in only the structure of an elongated gap 28portion and that of a connecting member 22. It is optional whethercleaning means 30 are to be provided or not, but for completely solvingthe problem of dust in the clean room it is desirable to provide thecleaning means 30. The work conveying system 10 of this secondembodiment or the horizontal moving means 12 used therein is providedwith at least one linear moving mechanism. For example, there is a casewhere plural linear moving mechanisms are used in combination toconstitute a horizontal moving means 12 which can move arbitrarily in ahorizontal plane, or there is a case where only one linear movingmechanism is provided to constitute a horizontal moving means which canmove on only one horizontal line. There also can be a case where onlyone linear moving mechanism is provided to constitute a vertical movingmeans which can move on only one vertical line.

[0087] In the linear moving mechanism provided in the work conveyingsystem 10 of this second embodiment or in the horizontal moving means 12used therein, in the portion of the elongated gap 28 in which theconnecting member 22 for connecting the slider 21 to the traveling body20 extends through the duct 17 and travels along the traveling path A,there is disposed a deformable sealing means 40 which covers theelongated gap 28 portion without obstructing the travel of theconnecting member 22. The sealing means 40 also plays the role ofminimizing the gap in the elongated gap 28 portion in order to enhancethe dust sucking effect by the fans 31 in the cleaning means 30.

[0088] As shown in FIGS. 4, 7, and 8, the sealing means 40 correspondsto an expansion member 41 which is in a bellows shape and which extendsnaturally in a normal condition to permit sealing of the elongated gap28 portion. In this second embodiment, in front of the connecting member22 as seen in the traveling direction (indicated with arrow B) of theconnecting member 22 there are provided a first seal holding member 51for holding the expansion member 41 in an initially closed state and afirst seal opening member 52 for subsequently opening the expansionmember 41 when the connecting member 22 passes the elongated gap 28portion. Further, at the rear of the connecting member 22 there areprovided a second seal opening member 53 for holding the expansionmember 41 in an initially opened state and a second seal holding member54 for subsequently closing the expansion member 41 when the connectingmember 22 passes the elongated gap 28 portion.

[0089] The first and second seal holding members 51, 54 and the firstand second seal opening members 52, 53 are all rollers, which aresupported rotatably at both ends of L-shaped roller support members 55and 56 respectively, the roller support members 55 and 56 being fixedlymounted to both end portions of a travel assist member 50, whereby therollers are positioned fixedly with respect to the travel assist member50 and the connecting member 22. The travel assist member 50 is in anelongated shape of such a size as encloses the connecting member 22 inside view and is fixed in the traveling direction to a nearly centralpart in the longitudinal direction (the direction perpendicular to thetraveling direction) of the connecting member 22. The travel assistmember 50 is provided at both ends thereof with tapered portions 50 aand 50 b which extend outwardly downward.

[0090] The first seal holding member 51, which is located in front ofthe front tapered portion 50 a of the travel assist member 50, presses aflat lower end portion 41 a of the expansion member 41 from above tomaintain a state of closed seal (see FIG. 8), while the first sealopening member 52, which is located at a rear shoulder portion of thefront tapered portion 50 a of the travel assist member 50, is mounted soas to be exposed upward slightly partially while being buried into arecess 50 c (see FIGS. 6 and 7) formed therein. The first seal openingmember 52 pushes up the flat lower-end portion 41 a of the expansionmember 41 from below to hold an opened state of seal (see FIG. 7). Bysuch operations of the first seal holding member 51 and the first sealopening member 52, the travel of the connecting member 22 and that ofthe travel assist member 50 within the elongated gap 28 are assistedwhile the seal of the elongated gap 28 is ensured.

[0091] The second seal opening member 53, which is located at a frontshoulder portion of the rear tapered portion 50 b in the travel assistmember 50, is mounted so as to be exposed upward slightly partiallywhile being buried into a recess 50 c formed therein and pushes the flatlower-end portion 41 a of the expansion member 41 from below to maintainan opened state of seal (see FIG. 7). The second seal holding member 54is located behind the rear tapered portion 50 b of the travel assistmember 50 and presses the flat lower-end portion 41 a of the expansionmember 41 from above to restore a closed state of seal (see FIG. 8). Bysuch operations of the second seal opening member 53 and the second sealholding member 54, the travel of the connecting member 22 and that ofthe travel assist member 50 within the elongated gap 28 are continuouslyassisted and a positive seal of the elongated gap 28 is recovered.

[0092] Since this second embodiment is constructed as above, there canbe obtained the following effects.

[0093] As in the first embodiment, the traveling body 20 as oneconstituent of the linear moving mechanism provided in the workconveying system 10 or in the horizontal moving means 12 used therein isadapted to engage the guide portion 18 a located in the interior of thetraveling path A covered with the duct 17 and travel through theinterior space of the traveling path A, so that dust generated from theslide portion where the traveling body 20 and the guide portion 18 a areengaged with each other is confined into the duct 17 and the possibilityof its leaking out into the exterior clean room is decreased. Besides,since the motor 23 serving as a drive source of the traveling body 20 isintegral with the traveling body 20, the drive portion (including thedrive motor 23, pinion 24 and rack 25) of the traveling body 20 is alsopositioned in the interior of the traveling path A and dust generatedfrom the drive portion is less likely to leak out into the clean room.In this second embodiment, moreover, the deformable sealing means 40which covers the elongated gap 28 portion without obstructing the travelof the connecting member 22 is disposed in the elongated gap 28 portionin which the connecting member 22 for connecting the slider 21 to thetraveling body 20 extends through the duct 17 and travels along thetraveling path A, so that the proportion of dust leaking out into theclean room through the elongated gap 28 is greatly decreased.Consequently, it becomes possible to keep the interior of the clean roomat a high degree of cleanness.

[0094] Further, the slide portion between the traveling body 20 and theguide portion 18 a and the drive portion of the traveling body 20 arepositioned nearly centrally, or in the vicinity thereof, in the interiorof the traveling path A covered with the duct 17, that is, the slideportion and the drive portion are positioned relatively far from theelongated gap 28, and therefore the possibility that the dust generatedfrom the slide portion and the drive portion may be discharged into theclean room through the elongated gap 28 is so much decreased.Consequently, the interior of the clean room can be kept at a stillhigher degree of cleanness.

[0095] The sealing means 40 is constituted as a bellows-like expansionmember 41 and, when looking in the traveling direction (indicated witharrow B) of the connecting member 22, in front of the connecting member22 are disposed the first seal holding member 51 for holding theexpansion member 41 in an initially closed state and the first sealopening member 52 for subsequently opening the expansion member 41 whenthe connecting member 22 travels through the elongated gap 28, while atthe rear of the connecting member 22 are disposed the second sealopening member 53 for maintaining the expansion member 41 in aninitially opened state and the second seal holding member 54 forsubsequently closing the expansion member 41 when the connecting member22 travels through the elongated gap 28. Therefore, the travel of theconnecting member 22 and that of the travel assist member 50 within theelongated gap 28 can be assisted while ensuring a positive seal of theelongated gap 28.

[0096] Further, in the case where the sealing means 40 is constituted asthe expansion member 41 which is bellows-like and which extendsnaturally in a normal condition to seal the elongated gap 28 portion,all that is required for sealing is disposing a bellows-like expansionmember in the elongated gap 28 portion which expansion member iscommonly used as a sealing member or as a protective cover, wherebythere can be easily obtained a deformable sealing means 40 which coversthe elongated gap 28 portion without obstructing the travel of theconnecting member 22.

[0097] The shape of the expansion member 41 serving as the sealing means40 may be modified as in FIG. 9. In this modified example, projectingportions 41 b and 41 c having a small downward length are formed alonginner and outer side edges of the flat lower-end portion 41 a of theexpansion member 41. With such projecting portions 41 b and 41 c, whenthe expansion member 41 has been extended to seal the elongated gap 28portion, there is no fear of the flat lower-end portion 41 a of theexpansion member 41 being disengaged from the upper edge on theelongated gap 28 side of the lower duct half 17 b. Also when the flatlower-end portion 41 a of the expansion member 41 is pushed up frombelow by the first and second seal opening members (rollers) 52 and 53,the flat lower-end portion 41 a is not disengaged from the upper edgesof the first and second seal opening members 52, 53 and the travelassist member 50, thus ensuring a stable seal of the elongated gap 28portion.

[0098] Next, a description will be given below of an embodiment (thirdembodiment) of the invention described in the foregoing ninth aspect.

[0099] In a linear moving mechanism provided in a work conveying system10 of this third embodiment, though not shown, a sealing means 40 isconstituted by an expansion member which normally extends with amagnetic force to seal the elongated gap 28. In this point the workconveying system 10 of this third embodiment is different from theprevious second embodiment, but is not different in the other points, soa detailed explanation thereof will be omitted.

[0100] Since this third embodiment is constructed as above, there can beattained the following effects.

[0101] By imparting magnetism to a lower edge of a commonly-usedexpansion member which lower edge extends along the elongated gap 28,for example, to the flat lower-end portion 41 a of the expansion member41 in the second embodiment, and by attracting the lower edgemagnetically, the expansion member 41 can be extended to cover theelongated gap 28 portion, so that the elongated gap 28 portion can besealed positively at a portion where the connecting member 22 does notpass. Besides, there is no obstacle to a smooth travel of the connectingmember 22. Further, there can be obtained the same effects as in thesecond embodiment.

[0102] Next, reference will be made below to an embodiment (fourthembodiment) of the invention described in the foregoing eleventh aspect,which is illustrated in FIGS. 10 to 12.

[0103]FIG. 10 is a partial sectional side view of a linear movingmechanism provided in a work conveying system of the fourth embodiment,as cut at a position corresponding to line IV-IV in FIG. 2 and as seenin the arrowed direction, FIG. 11 is a sectional view as seen in thearrowed direction XI-XI in FIG. 10, and FIG. 12 is a sectional view asseen in the arrowed direction XII-XII in FIG. 10. Portions common to thework conveying system of the second embodiment are identified by thesame reference numerals as in the second embodiment.

[0104] In a linear moving mechanism provided in a work conveying system10 of this fourth embodiment, as shown in FIGS. 10 to 12, a sealingmeans 40 is constituted by a chain 42, which normally hangs downnaturally to seal the elongated gap 28. The first and second sealholding members 51, 54, the first and second seal opening members 52,53, and associated components, which are used in the second embodiment,are not used in this fourth embodiment.

[0105] In the lower edge of the upper duct half 17 a of the duct 17, asshown in FIGS. 11 and 12, a groove 57 where the chain 42 can pop in andout with its vertical movement is formed throughout the overall lengthof the duct 17. According to this construction, when the connectingmember 22 passes the elongated gap 28 portion and pushes the chain 42upward in the passing position, the chain 42 will rise while beingguided by the groove 57 and enters the groove, so that the elongated gap28 portion can be sealed positively without obstructing a smooth travelof the connecting member 22. The work conveying system 10 of this fourthembodiment is different in the above point from the second embodiment,but there is no difference in other points, so a detailed descriptionwill be omitted.

[0106] Since this fourth embodiment is constructed as above, by merelydisposing a chain as a commonly-used part in the elongated gap 28portion there can be easily obtained a deformable sealing means 40 whichcovers the elongated gap 28 without obstructing the travel of theconnecting member 22. Additionally, like the second embodiment, therecan be obtained excellent effects based on the use of the sealing means40.

[0107] Description will now be directed to an embodiment (fifthembodiment) of the invention described in the foregoing twelfth aspect,which is illustrated in FIGS. 13 and 14.

[0108]FIG. 13 is a partial sectional side view of a linear movingmechanism provided in a work conveying system of this fifth embodiment,as cut in a position corresponding to line IV-IV in FIG. 2 and as seenin the arrowed direction, and FIG. 14 is an enlarged sectional view asseen in the arrowed direction XIV-XIV in FIG. 13. Portions common to thework conveying system of the second embodiment are identified by thesame reference numerals as in the second embodiment.

[0109] In a linear moving mechanism provided in a work conveying systemof this fifth embodiment, as shown in FIGS. 13 and 14, a sealing means40 comprises a pair of upper and lower elastic tubular members 43 a, 43b having a bellows-like section. The pair of upper and lower elastictubular members 43 a, 43 b press the connecting member 22 constantlyfrom above and below, and when the connecting member 22 passes theelongated gap 28 portion, it travels while pushing aside the pair ofupper and lower elastic tubular members 43 a, 43 b upward and downwardrespectively (see FIG. 14), while after the connecting member 22 haspassed the elongated gap 28 portion, the pair of upper and lower elastictubular members 43 a and 43 b can immediately revert to their originalstate (see the left-hand cross sectional view in FIG. 13).

[0110] When passing the elongated gap 28 portion, the outer periphery ofthe connecting member 22 is pressed by the elastic tubular members 43 aand 43 b which have been pushed aside upward and downward respectivelyby the connecting member 22, so that also in this portion there isattained a satisfactory seal. In FIG. 13, a state of abutment of bothend edges when the pair of upper and lower elastic tubular members 43 a,43 b assume their original expanded state, as well as a pressed state ofthe outer periphery portion of the connecting member 22 when the tubularmembers 43 a and 43 b are in a vertically pushed and contracted state,are drawn in a rough manner to facilitate understanding.

[0111] As shown in FIG. 14, upper and lower end head portions of thepair of elastic tubular members 43 a and 43 b are circular in sectionand are inserted respectively into holes 58 formed respectively in alower end of the upper duct half 17 a of the duct 17 and an upper end ofthe lower duct half 17 b of the duct 17 (to be more specific, theelongated gap 28-side upper end of the base member 19 of the lower ducthalf 17 b), which lower and upper ends of the upper and lower ducthalves 17 a and 17 b define the elongated gap 28. Thus, the upper andlower end head portions of the elastic tubular members 43 a and 43 b aresupported and fixed by the duct halves 17 a and 17 b. The first andsecond seal holding members 51, 54, the first and second seal openingmembers 52, 53, and associated components, which are used in the secondembodiment, are not used in this fifth embodiment. The work conveyingsystem 10 of this fifth embodiment is different in the above point fromthe second embodiment, but is not different in other points, so adetailed description thereof will be omitted.

[0112] Since this fifth embodiment is constructed as above, by merelydisposing in the elongated gap 28 portion a pair of upper and lowerelastic tubular members as commonly-used parts, e.g., elastic tubularmembers (tubes) 43 a and 43 b which on being pressed assume a balloonshape in section, there can be easily obtained a deformable sealingmeans 40 which covers the elongated gap 28 without obstructing thetravel of the connecting member 22. In addition, as in the secondembodiment, there can be obtained excellent effects based on the use ofthe sealing means 40.

[0113] In this fifth embodiment, the pair of upper and lower elastictubular members 43 a, 43 b which constitute the sealing means 40 may bemodified like a pair of upper and lower elastic tubular members 44 a, 44b each having a balloon-shaped section, as shown in FIGS. 15 and 16.FIG. 15 is a sectional view of the modified example, different in cutposition from FIG. 14, and FIG. 16 is a sectional view of the modifiedexample, same in cut position as FIG. 14. In FIG. 16, the connectingmember 22 passes the elongated gap 28 while pushing aside the pair ofupper and lower elastic tubular members 44 a, 44 b upward and downwardrespectively, while such is not the case in FIG. 15.

[0114] Even with such a pair of upper and lower elastic tubular members44 a, 44 b, there can be attained the same function and effect as thatof the pair of upper and lower elastic tubular members 43 a, 43 b. Inthe duct 17 which defines the elongated gap 28, the lower end of theupper duct half 17 a and the upper end of the lower duct 17 b arerecessed at 59 so as to receive therein and fix base ends of the pair ofupper and lower elastic tubular members 44 a, 44 b, respectively, asshown in the figures.

[0115] The present invention is not limited to the above first to fifthembodiments, but various modifications may be made within the scope notdeparting from the gist of the invention.

What is claimed is:
 1. A work conveying system comprising at least awork holding means for holding a work and a horizontal moving means formoving said work holding means horizontally in an upper ceiling spacewithin a clean room, said work being conveyed to each of pluralprocessing apparatuses while circulating among said processingapparatuses in the clean room, wherein: said horizontal moving means hasat least one linear moving mechanism, said linear moving mechanismcomprising: a traveling path covered with a duct and having a guideportion in the interior thereof; a traveling body adapted to engage saidguide portion and travel through an interior space of said travelingpath; and a slider connected to said traveling body and adapted totravel together with said traveling body in the exterior of saidtraveling path, said work holding means or another linear movingmechanism being attached to said slider, and cleaning means are disposedat suitable intervals in said traveling path to clean the air presentwithin the traveling path and discharge the cleaned air to the exterior.2. A work conveying system according to claim 1, wherein a drive source,a drive mechanism, and a power supply means, which are for saidtraveling body, are accommodated in the interior of said traveling path,at least said drive source being integral with said traveling body.
 3. Awork conveying system according to claim 1 or claim 2, wherein a basemember serving as a base of a guide member having said guide portionconstitute a part of said duct, said guide member and said base memberbeing formed by integral molding of the same material.
 4. A workconveying system according to any of claims 1 to 3, wherein in saidhorizontal moving means a plurality of said linear moving mechanisms areused in combination to permit the horizontal moving means to movearbitrarily in a horizontal plane in the upper ceiling space within saidclean room.
 5. A work conveying system according to any of claims 1 to4, wherein said work holding means is attached to said slider through avertical moving means for moving said work holding means vertically. 6.A work conveying system comprising at least a work holding means forholding a work and a horizontal moving means for moving said workholding means horizontally in an upper ceiling space within a cleanroom, said work being conveyed to each of plural processing apparatuseswhile circulating among said processing apparatuses, wherein: saidhorizontal moving means has at least one linear moving mechanism, saidlinear moving mechanism comprising: a traveling path covered with a ductand having a guide portion in the interior thereof; a traveling bodyadapted to engage said guide portion and travel through an interiorspace of said traveling path; and a slider connected to said travelingbody and adapted to travel together with said traveling body in theexterior of said traveling path, said work holding means or anotherlinear moving mechanism being attached to said slider, and a deformablesealing means is provided in an elongated gap portion in which aconnecting member for connecting said slider to said traveling bodyextends through said duct and travels along said traveling path, saidsealing means covering said elongated gap portion without obstructingthe travel of said connecting member.
 7. A traveling path sealingstructure in a work conveying system, said work conveying systemincluding at least one linear moving mechanism, said linear movingmechanism comprising: a traveling path covered with a duct and having aguide portion in the interior thereof; a traveling body adapted toengage said guide portion and travel through an interior space of saidtraveling path; and a slider connected to said traveling body andadapted to travel together with said traveling body in the exterior ofsaid traveling path, a work holding means or another linear movingmechanism being attached to said slider, wherein a deformable sealingmeans is provided in an elongated gap portion in which a connectingmember for connecting said slider to said traveling body extends throughsaid duct and travels along said traveling path, said sealing meanscovering said elongated gap portion without obstructing the travel ofsaid connecting member.
 8. A traveling path sealing structure in a workconveying system according to claim 7, wherein said sealing means is anexpansion member in the shape of bellows which normally extendsnaturally to seal said elongated gap portion.
 9. A traveling pathsealing structure according to claim 7, wherein said sealing means is anexpansion member which normally extends by virtue of magnetism to sealsaid elongated gap portion.
 10. A traveling path sealing structure in awork conveying system according to claim 8 or claim 9, wherein whenlooking in the traveling direction of said connecting member, in frontof the connecting member are provided a first seal holding member forholding said sealing means in an initially closed state and a first sealopening member for subsequently opening said sealing member while saidconnecting member travels through said elongated gap portion, and at therear of said connecting member are provided a second seal opening memberfor holding said sealing means in an initially opened state and a secondseal holding member for subsequently closing the sealing member whilesaid connecting member travels through said elongated gap portion.
 11. Atraveling path sealing structure in a work conveying system according toclaim 7, wherein said sealing means is constituted by a chain andnormally hangs down naturally to seal said elongated gap portion.
 12. Atraveling path sealing structure in a work conveying system according toclaim 7, wherein said sealing means comprises a pair of upper and lowerelastic tubular members which press said connecting member constantlyfrom above and below, and when said connecting member travels throughsaid elongated gap portion, the connecting member travels while pushingaside said pair of upper and lower elastic tubular members vertically,while after passage of the connecting member, said pair of upper andlower elastic tubular members can immediately revert to their originalshape.